The present invention relates to electrostatic precipitators and, more particularly, to a spacer for maintaining in spaced, parallel relationship a pair of segmented collecting electrode panels, each panel comprised of a plurality of aligned collecting electrode plates suspended from a support beam.
In the operation of an electrostatic precipitator, a gas laden with entrained particulate material will pass through an electrostatic field established about a discharge electrode assembly disposed intermediate to grounded collecting electrode panels. The suspended particles become electrically charged as they pass through the electrostatic field and move to, under the influence of the electrostatic field, and deposit upon the grounded collecting electrode panels flanking the discharge electrode assembly.
Although the prior art includes various collecting electrode panel designs, collecting electrode panels are commonly constructed in modular form by suspending a plurality of successively aligned collecting electrode plates in end to end relationship to form the collecting electrode panel. Each collecting electrode plate is typically suspended from a support beam mounted in the top of the precipitator housing to extend downwardly in a vertical plane. Each individual plate is formed of sheet metal and typically ranges from 1 to 3 feet in width and typically from 30 to 50 feet in length. The typical spacings between the collecting electrode panels are from 9 to 12 inches. One common configuration of collecting electrode plate is shown in U.S. Pat. No. 4,240,810. As disclosed therein, each panel includes a central flat plate web portion extending between spaced end portions which comprise J-shaped stiffening beams. Generally, alignment brackets are provided so as to extend between successive aligned plates as a means of loosely locking the plates of a panel in alignment. Typically, such brackets are U-shaped and disposed with the base of the U-shaped bracket mounted to the J-shaped stiffening beam at the end of one plate such that the legs of the U-shaped bracket extend outwardly to engage the end of the next successive plate within the cavity of the U-shaped alignment bracket.
The horizontal spacing between adjacent, parallel collecting electrode panels is critical and both panels should be maintained equally distant from the discharge electrodes extending in a parallel plane midway the collecting electrodes. If one collecting electrode panel, or any part thereof, is closer to the discharge electrodes than its neighboring panel on the opposite side of the discharge electrodes, arcing of the voltage between the discharge electrode and the closer of the spaced collecting electrodes will occur at a lower voltage than the peak operating voltage of the precipitator. Such arcing will limit the strength of the field attainable and also lower the operating efficiency of the precipitators.
In order to maintain neighboring collecting electrode panels in properly spaced relationship, it is common to use horizontally extending spacer bars or cross braces which are attached to the panels to extend horizontally between adjacent panels and provide the necessary strength and rigidity to maintain the desired spacing between the collecting electrode panels. To install such braces, it is usually necessary for a worker to enter the precipitator housing when the precipitator is not in operation to manually install the braces, typically by welding or bolting. Generally, such a process is labor intensive, expensive and time-consuming. Examples of various prior art spacers are disclosed in U.S. Pat. Nos. 3,553,939; 4,007,023; 4,478,614; 4,519,818; and 4,559,064.
Accordingly, it is an object of the present invention to provide a simple, inexpensive spacer which may be readily installed in a labor efficient manner at one or more positions along the vertical interface between successive aligned plates of neighboring panels.